-----------+---------+---------+---------+---------+---------+--------- | 1. | 2. | 3. | 4. | 5. | 6. -----------+---------+---------+---------+---------+---------+--------- Carbon | 0·35 | 0·39 | 0·37 | 0·34 | 0·35 | 0·250 Silicon | 0·06 | 0·07 | 0·07 | 0·08 | 0·07 | 0·069 Sulphur | 0·062 | 0·061 | 0·062 | 0·061 | 0·061 | 0·046 Phosphorus | 0·061 | 0·061 | 0·061 | 0·063 | 0·062 | 0·058 Manganese | 0·870 | 0·875 | 0·866 | 0·864 | 0·800 | 0·636 Iron | 98·597 | 98·543 | 98·571 | 98·592 | 98·657 | 98·941 -----------+---------+---------+---------+---------+---------+--------- | 100·000 | 100·000 | 100·009 | 100·000 | 100·000 | 100·000 -----------+---------+---------+---------+---------+---------+--------- Many rails which have been broken in the line under traffic have been analyzed, and proved to be hard steel; while others, which have been bent into all sorts of shapes, but not broken during accidents or derailments, have also been tested, and proved to be of soft steel. Some engineers are advocates for a hard steel rail, and claim for it greater durability and longer wear; but even supposing such hard rail should possess a slight superiority over the soft rail, it is well to consider whether such assumed advantage is not obtained at the risk of incurring greater liability to fracture. It must be borne in mind that a rail, once placed in the road, is exposed to all the changes of temperature from heat to frost, and has frequently to sustain increased strains arising from loose sleepers, where the gravel or ballast has been disturbed during heavy rains.